Stenotelegraph
The Stenotelegraf , a suitcase word from shorthand and telegraphy , was the first stenography machine with an electromechanical functional principle. It was invented in 1890 by the French M. Cassagnes.
The stenotelegraph should output legible plain text instead of shorthand. Connected to a telegraphic line, it should also be able to transmit messages at high speed over long distances. It is not known whether it was actually used. In fact, however, he anticipated both the invention of the first electric typewriter around 1903 and the modern electric machine stenograph.
functionality
The stenography machine of the Italian Antonio Zucco-Michela, which had been used in the Italian Senate since 1880, served as the transmitter. Shorthand abbreviations could be entered via a keyboard like on a typewriter, which were coded in an alphabet of 20 symbols and printed on a strip of paper using printing types and a ribbon .
The stenotelegraph now connected each key to one pole of a battery, the other pole of which was earthed. The buttons were connected to the contact plates of a distributor disc, above which a metallic brush turned, which established contact between the distributor disc and the line. A similar distributor disc was set up at the receiving point. (Later Cassagnes increased the number of contact plates in the distributor disc in order to be able to telegraph more than one shorthand character with each revolution; instead of the signal of a single key, several are transmitted at the same time.)
Each key contact generated an electrical impulse that was transmitted to the printing unit via a line. The transmitted pulses were then transferred to a strip of paper with the aid of electromagnets that actuated printing types. Another electromagnet ensured the automatic transport of the paper strip.
Instead of shorthand, printing produced readable plain text , another innovation. It should be able to transcribe up to 200 words per minute .
The stenotelegraph should also be able to transmit messages over long distances. This could easily be done over a short distance by extending the line between the transmitter and receiver. For further connections the signal had to be amplified via relay stations . To increase the speed of transmission, the stenographic signals were first punched into a punched tape. This punched tape was then scanned electrically by another apparatus; Theoretically, the signals could then be transmitted over long distances, where they were to be transcribed in shorthand by a printing unit .
Theoretically, 288 words (in shorthand) should be able to be transmitted per minute over the Paris - Marseille route (approx. 900 km). The aim was to achieve 452 words per minute over the shorter and therefore better line from Paris to Brussels . This exceeded the speed of a human telegraph operator (estimated 25–50 words per minute in plain text) many times over. The stenotelegraph was thus a reaction to the increasing pressure on telecommunications technology to have to transmit ever larger amounts of data ever faster.
literature
- H. Despeissis: Sténo-Télégraphie: Nouveau système de télégraphie Brevet p. G.- A. Cassagnes, Ing.-Civ. Impr. Bourdarie, Paris 1889.
Web links
- Le Sténotélégraphe. In: La Nature. No. 891, June 28, 1890, p. 4. (on the invention of the stenotelegraph; French)
- Steno-Telegraphy. In: The Manufacturer and Builder. Volume 23, February 1891, p. 35. (babel.hathitrust.org) (English)